This invention relates generally to assessment of lower extremity function for a human body, and more particularly to a method and an apparatus for assessing muscle strength, balance, endurance, coordination for a human body.
Physical rehabilitation is an important and oftentimes necessary step for improving an individual""s state of health, particularly after the individual""s body has undergone a traumatic event, such as an injury or surgical procedure. Rehabilitation of the lower extremity of the body is commonplace, particularly in light of injuries suffered from work related injuries or participation in any of numerous sports requiring lower extremity contribution, such as running (i.e., baseball, basketball, football, soccer and tennis), skiing (water skiing or snow skiing), cycling, weight lifting, roller blading and hockey. Furthermore, rehabilitation after a lower extremity injury or surgical procedure is critical for returning a patient to full functional capacity. Proper and effective rehabilitation of the lower extremity of the body requires continual assessment of the lower extremity function. For example, standardized data relating to the capabilities of muscle groups in the lower extremities are needed in order to properly guide a patient""s rehabilitative treatment after suffering from a lower extremity injury (i.e., hip, leg, knee, ankle or foot injury) or following a lower extremity surgical procedure (i.e., reconstructive knee surgery) and also to properly evaluate the patient""s overall physical ability to return to functional activities such as sports, work and general activities of daily living. Lower extremity function is generally evidenced by the integration of strength, balance, endurance and coordination.
Lower extremity function has been studied for many years. Several clinical tests have been used to assess lower extremity function after suffering from lower extremity injuries. For example, much discussion has focused on the most effective approach to rehabilitation of a lower extremity (i.e., hip, leg, knee, ankle or foot injury), specifically the use of open kinetic chain (OKC) exercises and closed kinetic chain exercises (CKC). Similarly, much discussion has focused on whether OKC exercises or CKC exercises are the more valid and reliable test for evaluating a patient""s overall ability to return to functional activities such as sports, work and activities of daily living, without further risk of injury. Much controversy exists in the literature as to the correlation between these two testing philosophies. Several studies have demonstrated a positive correlation between OKC and CKC testing, while others have demonstrated little if any correlation. As is the case with rehabilitation philosophies, OKC and CKC testing methods have both been utilized. Recently however, the use of CKC exercises has been advocated due to many documented advantages over OKC exercises.
Of the CKC tests performed, hop tests are most commonly used to assess lower extremity function. The hop test provides an assessment of functional strength, balance, endurance and coordination of the entire lower extremity. The hop test involves single-leg hopping across a floor. Unfortunately, the hop test can not be safely implemented until the later stages of the rehabilitation process. This is in part due to the requirement, associated with the hop test, that the muscles, which are still undergoing rehabilitation, must exhibit not yet attainable explosive exertion upon vertical takeoff. This is also in part due to the tremendous and potentially damaging forces that the muscles, ligaments, joints, cartilage and surrounding supportive tissues, which are still undergoing rehabilitation, must endure upon gravitational impact. Another CKC test is based on an inclined squat or leg press test. Even though this test assesses strength and endurance in the CKC environment, the inclined squat or leg press test does not take into account the balance issue and the coordination issue because the patient is resting on the inclined squat or leg press machine.
Of the OKC tests, isokinetic testing remains the standard mainly because of the ability to perform isolated lower extremity muscle strength testing. The isokinetic test provides an isolated strength assessment of the quadriceps and hamstring muscles on an individual basis and typically uses a sophisticated testing machine having a mechanical strength-electronic measuring instrument in which force is exerted by the patient""s foot against a lever-arm attached to a dynamometer and subsequently electronically measured while the patient remains sitting on the machine. Unfortunately, the isokinetic test does not assess balance or coordination and does not assess the entire lower extremity as one functional unit. Additionally, the isokinetic test is capital intensive for the rehabilitative administrating facility because the test typically requires the use of mechanical strength-electronic measuring instrumentation that is not only expensive but also sophisticated, thus requiring costly and time consuming training. Furthermore, the isokinetic test may also be cost intensive to the patient as charges related to the use of the mechanical strength-electronic measuring instrument are unfortunately not always reimbursed by insurance companies. With the advent of the managed care environment, isokinetic testing is not always clinically practical.
At the present time, there is no satisfactory test to assess muscle strength, balance, endurance, coordination and lower extremity function during rehabilitation of the lower extremity of the body that is also inexpensive and easy to administer on patients. As such, a need exists for other means of testing lower extremity function (e.g., the successful integration of strength, balance, endurance and coordination), and this test must be economical and easy for the clinician or healthcare professional to implement on patients. In particular, what is needed is a method and an apparatus for testing the lower extremity as one functional unit. Further needed is a method and an apparatus for testing the lower extremity that may be safely implemented during all stages of the rehabilitative process. More particularly, what is needed is a method and an apparatus for testing the lower extremity for an assessment of functional strength, balance, endurance and coordination of the entire lower extremity that is cost-effective and is simple to administer on patients.
The invention is a method and an apparatus for testing the entire lower extremity as one functional unit. More particularly, the invention is a method and an apparatus for testing the entire lower extremity for an assessment of functional strength, balance, endurance and coordination of the entire lower extremity. The invention may be safely implemented during all stages of the rehabilitative process. The invention is cost-effective and is simple to administer on patients.
The invented apparatus marks the maximum angle of movement at the hip, knee and ankle as the patient squats down using only a single test leg.
The invented lower extremity testing apparatus comprises a horizontally planar base having a knee tripodal portion and a hip tripodal portion adjustably coupled to the knee tripodal portion by a variable length connector, a knee post fixedly attached to the knee tripodal portion and vertically extending orthogonally away from the horizontal plane of the horizontally planar base, a hip post fixedly attached to the hip tripodal portion and vertically extending orthogonally away from the horizontal plane of the horizontally planar base, a knee bar that is adjustably connected to the knee post and a hip bar that is adjustably connected to the hip post. The knee tripodal portion may be releasably secured to the variable length connector by a locking fastener. The hip tripodal portion may be releasably secured to the variable length connector by a locking fastener. The knee bar may be releasably secured to the knee post by a locking fastener. The hip bar may be releasably secured to the hip post by a locking fastener.
In a preferred embodiment of the invention, the knee tripodal portion has a first central hollow pole having a diameter, a first lateral supporting pole fixedly attached to and extending perpendicularly away from the first central hollow pole, and a second lateral supporting pole fixedly attached to and extending perpendicularly away from the first central hollow pole to form a generally cross shape. The hip tripodal portion has a second central hollow pole having a diameter, a third lateral supporting pole fixedly attached to and extending perpendicularly away from the second central hollow pole, and a fourth lateral supporting pole fixedly attached perpendicularly to and extending perpendicularly away from the second central hollow pole to form a generally cross shape. The variable length connector is a cylindrical tube having a diameter that is less than the diameter of the first central hollow pole and the diameter of the second central hollow pole. The cylindrical tube of the variable length connector may be inserted and telescopically received within the first central hollow pole and the second central hollow pole to adjustably couple the first central hollow pole of the knee tripodal portion to the second central hollow pole of the hip tripodal portion. The first central hollow pole and the second central hollow pole may each be releasably secured to the cylindrical tube of the variable length connector by a locking fastener. The horizontally planar base, having the knee tripodal portion and the hip tripodal portion adjustably coupled to the knee tripodal portion by the variable length connector, is positioned along a horizontal plane of the floor and provides stability to the invented apparatus. The knee post is a hollow cylindrical tube having a diameter and fixedly attached to the first central hollow pole of the knee tripodal portion while extending vertically upward orthogonally away from the horizontal plane of the horizontally planar base. The knee bar has a diameter that is less than the diameter of the knee post. The knee bar may be inserted and telescopically received within the knee post to form a generally L shape. The knee bar may be releasably secured to the knee post by a locking fastener. The hip post is a hollow cylindrical tube having a diameter and fixedly attached to the second central hollow pole of the hip tripodal portion while extending vertically upward orthogonally away from the horizontal plane of the horizontally planar base. The hip bar has a diameter that is less than the diameter of the hip post. The hip bar may be inserted and telescopically received within the hip post to form a generally L shape. The hip bar may be releasably secured to the hip post by a locking fastener.
The variable length connector allows the invented apparatus to be horizontally adjusted by increasing or decreasing the distance between the knee tripodal portion and the hip tripodal portion depending upon a patient""s particular physical dimension, such as the distance between the hip and the knee of the patient. The knee post and the hip post allows the invented apparatus to be adjusted in height by vertically extending or retracting the knee bar and the hip bar orthogonally away from or toward the horizontal plane of the horizontally planar base to accommodate a patient""s particular physical dimension, such as the distance between the knee and the ankle of the patient. Adjustment of the distance between the knee tripodal portion and the hip tripodal portion, the height of the knee bar and the height of the hip bar during a trial single leg squat enables the clinician or healthcare professional to establish a desired and physically attainable degree of flexion (angle of bend or movement at a joint) to be achieved by the patient prior to undergoing lower extremity testing.
In operation, patients perform a trial single leg squat to a desired degree of flexion with each lower extremity to confirm an individual patient""s ability to complete a single leg squat in a specified range-of-motion (ROM). Next, the patient is positioned proximally within the invented apparatus which is specifically adjusted to allow for the desired degree of flexion to be physically attained by the particular patient while performing single leg squats during lower extremity testing. The distance between the knee tripodal portion and the hip tripodal portion, the height of the knee bar and the height of the hip bar are adjusted such that at the desired degree of flexion to be achieved while performing single leg squats during lower extremity testing, the midline of the patella contacts the midline of the knee bar and the hip (ischial tuberosity) contacts the midline of the hip bar. This desired test position will be standardized for each individual subject based on the angle of ankle dorsiflexion achieved during the transition between eccentric and concentric phases of the single leg squat. A dorsiflexion angle of 20 degrees, as measured in a closed kinetic chain (CKC) is used to standardize the desired test position. Test angles are determined using standard goniometric measurement techniques at the ankle and knee joints. An inclinometer is attached to the lateral aspect of the test thigh to monitor the angle of flexion of the knee during warm-up, trial and test repetitions.
From the starting position with the test leg in full extension and the non-test leg flexed at the hip, knee and ankle, the patient squats down until the test knee lightly contacts the knee bar and the test hip (ischial tuberosity) lightly contacts the hip bar. Upon contact with the knee bar and the hip bar, the patient returns to the starting position. The patient""s non-test knee and non-test hip are maintained in a flexed position to minimize hip substitution in the frontal and transverse planes of the body. During warm-up, trial and test repetitions, patients lightly contact the knee bar and the hip bar simultaneously to minimize biomechanical differences in squatting strategies. Furthermore, patients are not to xe2x80x9crestxe2x80x9d or xe2x80x9cunloadxe2x80x9d on the knee bar and the hip bar. One complete repetition is defined as successfully squatting from 0 degrees to the desired angle of flexion (i.e., 1xc2x0 to 90xc2x0) of the knee joint and simultaneously contacting the knee bar and hip bar lightly, without touching or holding onto any object for balance or xe2x80x9crestingxe2x80x9d or xe2x80x9cunloadingxe2x80x9d on the knee bar or the hip bar.
In a preferred embodiment, the patient performs five warm-up repetitions while touching or holding onto a stable object for balance, the patient then rests for thirty seconds, the patient then performs an additional five warm-up repetitions this time without touching or holding onto any object for balance, the patient then rests for one minute, next the patient performs a maximum number of repetitions as physically possible in 60 seconds without touching or holding onto any object for balance or xe2x80x9crestingxe2x80x9d or xe2x80x9cunloadingxe2x80x9d on the knee bar or the hip bar, and then the patient may rest and subsequently repeat the aforementioned steps for the opposite leg.
The principal object of the invention is to provide a method and an apparatus for testing the entire lower extremity as one functional unit.
Another, more particular object of the invention is to provide a method and an apparatus for testing the entire lower extremity for an assessment of functional strength, balance, endurance and coordination of the entire lower extremity.
Another object of the invention is to provide a method and an apparatus for testing the entire lower extremity that may be safely implemented during all stages of the rehabilitative process.
Another object of the invention is to provide a method and an apparatus for testing the entire lower extremity that is cost-effective and is simple to administer on patients.